California energy officials are recognizing the need to work together to prioritize a long list of transmission and distribution interconnection projects as the state’s load growth accelerates due to expected data center development. 

At an Aug. 11 joint agency workshop, representatives from the California Energy Commission, California Public Utilities Commission, CAISO and other entities discussed how to accelerate interconnection timelines in the Golden State, with conversations focusing on the various types of new load coming online and bringing out-of-state wind power to California’s borders. 

“In a big, complicated state like California … it’s really great to have this platform to do some level setting,” CEC Commissioner Andrew McAllister said at the workshop. 

“I’ve really learned to appreciate the complexity of our roles,” CEC Vice Chair Siva Gunda added. “One of the things we’re dealing with across demand forecasts, whether it’s distribution planning or integrated resource planning, is the uncertainty — the vast uncertainty — in demand, because of electrification, climate impacts and new loads that may come [or] may not come.” 

Gunda asked Neil Millar, CAISO vice president of infrastructure and operations planning, to explain how the ISO is thinking about protecting electricity rates while at the same time future-proofing investments in energy infrastructure and resources. 

“I think the most important part [of this effort] is about the sensitivity work that goes into considering options,” Millar said. “And part of that includes picking options that are always a good first step and not necessarily always … going for the fences with a transmission project.” 

Instead, agencies could focus on picking scalable options because, once a project is a few years down the path, there’s “always a risk that the load growth softens,” Millar said.  

“Then you’re not dependent on some next step in order to achieve the actual benefit of the plan,” Millar said. “Our focus has normally been to try to achieve the required in-service data, monitor the load growth, and make adjustments if necessary, but also to [consider] the sequencing of transmission projects.” 

Load forecasts in California and the West have been escalating, which increases energy resource and transmission requirements in the region, Millar said during his presentation. CAISO is dealing with new types of loads, such as those caused by data centers in particular, he said. 

CAISO’s 2025/26 transmission planning process continues to rely on accessing out-of-state resources, particularly wind, Millar said. These out-of-state wind resources will need more attention over the coming years to bring them to California, he added.  

Millar specifically highlighted 12 major transmission projects — each from CAISO’s transmission plans from 2018 to 2025 — that are under development. However, about 12.9 GW of renewable resources could be delayed due to transmission delays, Brian Biering, counsel for American Clean Power, California (ACP), said in a presentation at the workshop. As of April, the region has about 28.4 GW total of new renewable generation and storage resources with signed interconnection agreements, he said. 

To help solve these delays, ACP recommended energy officials consider requiring an independent transmission construction monitor (ITCM) that would increase the transparency and enhance staff understanding of transmission construction for projects above 1,000 MW. The ITCM should be able to request data directly from transmission owners and report directly to the CPUC and CAISO, Biering said. 

Investor-owned utilities in California have 715 transmission projects under development that have planned in-service dates between 2025 and 2033 and an expected cost of $1 million or greater, said Molly Sterkel, interim director of electricity supply, planning and costs at CPUC. Of those 715 projects, CAISO has approved 140, while 575 are non-approved, Sterkel said. 

California needs 100 GW of new resources by 2040, said Danielle Mills, CAISO principal of infrastructure policy development. The ISO has “more than sufficient resources in the queue to meet those needs,” Mills said. 

“In fact, we still worry sometimes … that we have too many projects in the queue that are lingering, that we need to find some alternative pathway for, either withdrawal or transitioning those resources to some other type of resource,” Mills said.